mcs/class/System.ComponentModel.Composition/Documentation/en/System.ComponentModel.Composition/CreationPolicy.xml

   1 <?xml version="1.0" encoding="utf-8"?>
   2 <Type Name="CreationPolicy" FullName="System.ComponentModel.Composition.CreationPolicy">
   3   <TypeSignature Language="C#" Value="public enum CreationPolicy" />
   4   <TypeSignature Language="ILAsm" Value=".class public auto ansi sealed CreationPolicy extends System.Enum" />
   5   <AssemblyInfo>
   6     <AssemblyName>System.ComponentModel.Composition</AssemblyName>
   7     <AssemblyVersion>4.0.0.0</AssemblyVersion>
   8   </AssemblyInfo>
   9   <Base>
  10     <BaseTypeName>System.Enum</BaseTypeName>
  11   </Base>
  12   <Docs>
  13     <remarks>
  14       <attribution license="cc4" from="Microsoft" modified="false" />
  15       <para>In the course of composition, the <see cref="T:System.ComponentModel.Composition.Hosting.CompositionContainer" /> needs instances of the objects described by exports in order to fill imports. If a one export is used to fill multiple imports, there are two possible behaviors. Either a single instance of the exported object is created, and a reference to the same object is given to every importer, or a separate instance of the exported object is created for each importer. </para>
  16       <para>Which behavior occurs depends on the <see cref="P:System.ComponentModel.Composition.PartCreationPolicyAttribute.CreationPolicy" /> property of the <see cref="T:System.ComponentModel.Composition.PartCreationPolicyAttribute" /> attached to the export and the <see cref="P:System.ComponentModel.Composition.ImportAttribute.RequiredCreationPolicy" /> of the <see cref="T:System.ComponentModel.Composition.ImportAttribute" />. Both of which will contain a value from the <see cref="T:System.ComponentModel.Composition.CreationPolicy" /> enumeration. If the policies are incompatible, that export will not be considered a match for the given import. The following table summarizes the interaction of these two properties.</para>
  17       <list type="table">
  18         <listheader>
  19           <item>
  20             <term>
  21               <para>
  22                 <see cref="P:System.ComponentModel.Composition.ImportAttribute.RequiredCreationPolicy" />
  23               </para>
  24             </term>
  25             <description>
  26               <para>Export's <see cref="P:System.ComponentModel.Composition.PartCreationPolicyAttribute.CreationPolicy" /> specifies <see cref="F:System.ComponentModel.Composition.CreationPolicy.Any" /> or none specified.</para>
  27             </description>
  28             <description>
  29               <para>Export's <see cref="P:System.ComponentModel.Composition.PartCreationPolicyAttribute.CreationPolicy" /> specifies <see cref="F:System.ComponentModel.Composition.CreationPolicy.Shared" /></para>
  30             </description>
  31             <description>
  32               <para>Export's <see cref="P:System.ComponentModel.Composition.PartCreationPolicyAttribute.CreationPolicy" /> specifies <see cref="F:System.ComponentModel.Composition.CreationPolicy.NonShared" /></para>
  33             </description>
  34           </item>
  35         </listheader>
  36         <item>
  37           <term>
  38             <para>
  39               <see cref="F:System.ComponentModel.Composition.CreationPolicy.Any" />
  40             </para>
  41           </term>
  42           <description>
  43             <para>A single, shared instance of the exported object will be created.</para>
  44           </description>
  45           <description>
  46             <para>A single, shared instance of the exported object will be created.</para>
  47           </description>
  48           <description>
  49             <para>A new instance of the exported object will be created for each importer.</para>
  50           </description>
  51         </item>
  52         <item>
  53           <term>
  54             <para>
  55               <see cref="F:System.ComponentModel.Composition.CreationPolicy.Shared" />
  56             </para>
  57           </term>
  58           <description>
  59             <para>A single, shared instance of the exported object will be created.</para>
  60           </description>
  61           <description>
  62             <para>A single, shared instance of the exported object will be created.</para>
  63           </description>
  64           <description>
  65             <para>The export will not be considered a match for the import.</para>
  66           </description>
  67         </item>
  68         <item>
  69           <term>
  70             <para>
  71               <see cref="F:System.ComponentModel.Composition.CreationPolicy.NonShared" />
  72             </para>
  73           </term>
  74           <description>
  75             <para>A new instance of the exported object will be created for each importer.</para>
  76           </description>
  77           <description>
  78             <para>The export will not be considered a match for the import.</para>
  79           </description>
  80           <description>
  81             <para>A new instance of the exported object will be created for each importer.</para>
  82           </description>
  83         </item>
  84       </list>
  85     </remarks>
  86     <summary>
  87       <attribution license="cc4" from="Microsoft" modified="false" />
  88       <para>Specifies when and how a part will be instantiated.</para>
  89     </summary>
  90   </Docs>
  91   <Members>
  92     <Member MemberName="Any">
  93       <MemberSignature Language="C#" Value="Any" />
  94       <MemberSignature Language="ILAsm" Value=".field public static literal valuetype System.ComponentModel.Composition.CreationPolicy Any = int32(0)" />
  95       <MemberType>Field</MemberType>
  96       <AssemblyInfo>
  97         <AssemblyVersion>4.0.0.0</AssemblyVersion>
  98       </AssemblyInfo>
  99       <ReturnValue>
 100         <ReturnType>System.ComponentModel.Composition.CreationPolicy</ReturnType>
 101       </ReturnValue>
 102       <Docs>
 103         <summary>
 104           <attribution license="cc4" from="Microsoft" modified="false" />
 105           <para>Specifies that the <see cref="T:System.ComponentModel.Composition.Hosting.CompositionContainer" /> will use the most appropriate <see cref="T:System.ComponentModel.Composition.CreationPolicy" /> for the part given the current context. This is the default <see cref="T:System.ComponentModel.Composition.CreationPolicy" />. By default, <see cref="T:System.ComponentModel.Composition.Hosting.CompositionContainer" /> will use <see cref="F:System.ComponentModel.Composition.CreationPolicy.Shared" />, unless the <see cref="T:System.ComponentModel.Composition.Primitives.ComposablePart" /> or importer requests <see cref="F:System.ComponentModel.Composition.CreationPolicy.NonShared" />.</para>
 106         </summary>
 107       </Docs>
 108     </Member>
 109     <Member MemberName="NewScope">
 110       <MemberSignature Language="C#" Value="NewScope" />
 111       <MemberSignature Language="ILAsm" Value=".field public static literal valuetype System.ComponentModel.Composition.CreationPolicy NewScope = int32(3)" />
 112       <MemberType>Field</MemberType>
 113       <AssemblyInfo>
 114         <AssemblyVersion>4.0.0.0</AssemblyVersion>
 115       </AssemblyInfo>
 116       <ReturnValue>
 117         <ReturnType>System.ComponentModel.Composition.CreationPolicy</ReturnType>
 118       </ReturnValue>
 119       <Docs>
 120         <summary>To be added.</summary>
 121       </Docs>
 122     </Member>
 123     <Member MemberName="NonShared">
 124       <MemberSignature Language="C#" Value="NonShared" />
 125       <MemberSignature Language="ILAsm" Value=".field public static literal valuetype System.ComponentModel.Composition.CreationPolicy NonShared = int32(2)" />
 126       <MemberType>Field</MemberType>
 127       <AssemblyInfo>
 128         <AssemblyVersion>4.0.0.0</AssemblyVersion>
 129       </AssemblyInfo>
 130       <ReturnValue>
 131         <ReturnType>System.ComponentModel.Composition.CreationPolicy</ReturnType>
 132       </ReturnValue>
 133       <Docs>
 134         <summary>
 135           <attribution license="cc4" from="Microsoft" modified="false" />
 136           <para>Specifies that a new non-shared instance of the associated <see cref="T:System.ComponentModel.Composition.Primitives.ComposablePart" /> will be created by the <see cref="T:System.ComponentModel.Composition.Hosting.CompositionContainer" /> for every requestor.</para>
 137         </summary>
 138       </Docs>
 139     </Member>
 140     <Member MemberName="Shared">
 141       <MemberSignature Language="C#" Value="Shared" />
 142       <MemberSignature Language="ILAsm" Value=".field public static literal valuetype System.ComponentModel.Composition.CreationPolicy Shared = int32(1)" />
 143       <MemberType>Field</MemberType>
 144       <AssemblyInfo>
 145         <AssemblyVersion>4.0.0.0</AssemblyVersion>
 146       </AssemblyInfo>
 147       <ReturnValue>
 148         <ReturnType>System.ComponentModel.Composition.CreationPolicy</ReturnType>
 149       </ReturnValue>
 150       <Docs>
 151         <summary>
 152           <attribution license="cc4" from="Microsoft" modified="false" />
 153           <para>Specifies that a single shared instance of the associated <see cref="T:System.ComponentModel.Composition.Primitives.ComposablePart" /> will be created by the <see cref="T:System.ComponentModel.Composition.Hosting.CompositionContainer" /> and shared by all requestors.</para>
 154         </summary>
 155       </Docs>
 156     </Member>
 157   </Members>
 158 </Type>